1. Field of the Invention
The present invention relates to an image storage apparatus and an image storage method for use with a digital camera having a continuous-shooting function.
2. Description of the Related Art
Heretofore, an image capture apparatus has been proposed which is adapted to record images continuously captured in past times. Such an apparatus sequentially stores images captured at a predetermined frame rate into a buffer memory. When any trigger is occurred, a plurality of frames of image date stored in the buffer memory are all read from the buffer memory and then recorded into an image memory. Thereby, images captured in past time, earlier than the occurrence of the trigger, can be recorded in the image memory.
The buffer memory includes a first buffer and a second buffer. In storing image data into the buffer memory, newly captured image data is sequentially stored into the first buffer. When the first buffer is filled up, one out of the oldest images is copied into the second buffer and the copied oldest image is erased from the first buffer. Thereby, limited capacity of the buffer memory is allowed to store even an image captured in less recent past time. When the second buffer is also filled up, the oldest images are sequentially erased from the second buffer.
Conventionally, a storage area for newer images in the first buffer is secured by means of thinning out image data stored in the first buffer and copying image data from the first buffer into the second buffer. That is, the process of copying image data is indispensable, which might increase the processing burden on the CPU or delay other processing.